1. Field of Invention
The present invention relates to reset circuit of clock circuit to efficiently cause a reset on the real time circuit.
2. Description of Related Art
Real time clock (RTC) has broad applications, such as applications in various electronic circuits with time information. The time information can be used to record the time for each event occurred. Therefore, the real time clock is a timing reference information.
Usually, the operation of the RTC is using the static capacitor for storing charges. When the battery is detached, the action time for the RTC would be different with respect to the status of the electric consumption of the RTC. The action time is then affected by the static capacitance level and IC fabrication process. In this situation, when the charges are completely consumed, the RTC stop accordingly. When the battery is attached again, the RTC needs a rest signal to reset the whole circuit, and makes a warning about invalidity and the time need to be reset. However, the duration of the reset signal and the activation time of the RTC are both affected by the supplied voltage, difference of circuit, device and so on.
In other words, how to assure the effective rest of the RTC is one of the issues.